From mboxrd@z Thu Jan 1 00:00:00 1970 MIME-Version: 1.0 In-Reply-To: <635018e058076d45e5d6bcf01860138a@ladd.quanstro.net> References: <635018e058076d45e5d6bcf01860138a@ladd.quanstro.net> Date: Tue, 22 Dec 2009 09:56:12 -0800 Message-ID: Subject: Re: [9fans] Design of webfs and webcookies From: Russ Cox To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net> Content-Type: text/plain; charset=UTF-8 Topicbox-Message-UUID: b237ff88-ead5-11e9-9d60-3106f5b1d025 > what's really wanted here is an atomic create/write/close so that > one process (we don't care which one) is responsible for the whole > file. i think you could get this behavior by creating a temporary > keyfile and then an rename (wstat), which is atomic. what's really wanted here (and i wrote the code) is an atomic open/read/write/close, so that different processes can update the file in sequence without stepping on or losing each others changes. DMEXCL provides that; create+(remove+)wstat does not. russ